Jack fastener employing a bolt having two-threaded sections



June 11, 1963 N. WASSERMAN 3,093,025

JACK FASTENER EMPLOYING A BOLT HAVING TWO-THREADED SECTIONS Filed May 29, 1959 FIG.

lNl/ENTOR 1v. WASSERMAN A TTORNEV 3,093,025 JACK FASTENER EMFLOYMG A BOLT HAVE'JG TWO-TIEEADED SECTIQNS Norman Wasserman, Bayside, N.Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N.Y., a

corporation of New York Filed May 29, 1959, Ser. No. 816,963 7 Claims. (Cl. 85-1) This invention relates to fastener devices and more particularly to a fastener for securing an object against a supporting strip.

Fasteners of the type considered herein are employed in certain PBX board, as an example, the jack strips thereof being suitably shaped to be clamped against the framing or stile strips of the board by one or more fastener devices secured to the stile strips. A fastener includes a bolt member and a clamping bar or butterfly member which moves to a clamping position when the bolt is rotated in one direction. In the clamping position, the fastener applies pressure to the jack strip and clamps it against the stile strip. The pressure of the butterfly against the jack strip sometimes produces cold flow of the jack strip which prevents rotation of the butterfly to a releasing position when the bolt is rotated in the other direction. The failure of the butterfly to return to a releasing position prevents quick removal of the jack strip from the board when repairs thereto are necessary. In addition to the failure of the butterfly to return to a release position, the jack fastener often becomes detached from the stile strip when the bolt is rotated excessively in the other direction. The replacement of a fastener is time consuming since the connecting wires to the terminals of the jack strip prevent ready access to the stile strips of the board.

An object of the present invention is an improved fastener device for securing an object to a supporting strip.

A more specific object of the present invention is a fastener device having positive-action upon operation thereof.

Another specific object of the present invention is a fastener which cannot be accidentally removed from a supporting strip.

A feature of the present invention is a bolt and butterfly assembly for securing an object against a supporting strip, the assembly including driving means for vertical and rotational movement of the butterfly with respect to the object as the bolt is rotated.

A specific feature of the present invention is a bolt having two threaded sections of different diameter and pitch, the larger diameter section being threaded into a clamping bar or butterfly including a tapped bushing and means for driving the butterfly by friction as rotaton of the bolt occurs.

Another specific feature of the present invention is a fastener comprising a bolt, spacer, and butterfly assembly secured to a stile strip, the spacer means preventing accidental removal of the assembly from the stile strip.

In an illustrative embodiment, the fastener is secured to a supporting strip having at least one tapped hole therein and an indexing ridge. The fastener includes a screw having two threaded sections of different diameter and pitch and a clamping bar or butterfly having a tapped bushing therein. The larger diameter section of the screw is threaded through the tapped bushing. The smaller diameter section is threaded into the tapped hole of the supporting strip until the butterfly is seated on the strip in the clamping position wherein the butterfly is extended away from the indexing ridge on the strip. By rotating the screw out of the tapped hole, the butterfly is elevated off the strip and turned to the release position wherein the butterfly is in line with and restrained by the indexing 3,93,625 Patented June 11, 1963 ridge. A spacer inserted between the head of the screw and the butterfly limits the distance the screw may be rotated out of the tapped hole. Rotating the screw into the tapped hole returns the butterfly to the clamping position.

Other objects and features of the present invention will hereinafter become more fully apparent from the following detailed description taken in conjunction with the appended drawing in which:

FIG. 1 is a rear face view of a supporting strip showing the operation of one embodiment of the present invention in clamping and releasing one end of an object to a supporting strip;

FIG. 2 is a view along the line 2-2 of FIG. 1 showing the structural details of the fastener of FIG. 1 in a clamping position;

FIG. 2A is a top and side view of a locking spacer employed with the fastener of FIG. 2;

FIG. 3 is a rear face view of another embodiment of the present invention in clamping and releasing one end of an object to a supporting strip;

FIG. 3A is a top and side view of a locking spacer employed wi h the fastener of FIG. 3; and

FIG. 4 is a view along the line 4-4 of FIG. 3 showing the structural details of the fastener of FIG. 3 in a clamping position.

As shown in FIG. -l, the fastener 20 of the present invention is employed to fasten an object 22, such as a jack strip of a PBX board, to a supporting or stile strip 24 of the board, the strip 24 including an indexing ridge 25. A series of fasteners are threaded into tapped holes 23 spaced at regular intervals along the stile strip. Each fastener is adapted to clamp an end of the jack strip against the stile strip of the PBX board.

The details of one embodiment of the present invention are shown in FIG. 2, the fastener 20 comprising a flat-headed bolt or screw 26 having a first threaded section 28 which is larger in diameter and different in pitch than a second threaded section 30. The section 28, as shown, has left-hand threading thereon and is threaded into a clamping bar or butterfly 32 having a tapped hole 33 therein which includes a plastic bushing 34, one example of the material of the bushing being nylon. The butter fly includes a relief 36 (see FIG. 1) at one corner thereof and each of the remaining corners has a small radius therein to prevent interference when a plurality of fasteners are operated in close positions. The threaded section 3% of the fastener has right-hand threads thereon and is threaded into one of the tapped holes 23 located on the stile strip. Although the threading of the sections 28 and 30 has been shown as left-handed and right-handed, respectively, it is obvious that the bolt could as well be made with right-handed and left-handed threading, respectively. Completing the assembly of the fastener is a locking spacer 38, shown in FIG. 2A, which clips about the bolt between the head thereof and the butterfly.

The fastener is assembled by turning the threaded section 28 into the tapped hole 33 as far as possible or until the butterfly engages the head of the screw. Next, using a conventional screwdriver, the threaded section 30 is threaded into one of the tapped holes 23 until the butterfly is approximately one thirty-second inch above the ridge 25. At this point, the butterfly is held extended away from the ridge while the screw is advanced into the hole 23, the relief of the butterfly being adjacent to the ridge for reasons more apparent hereinafter. Upon engaging the strip 22, continued rotation of the screw will cause the butterfly to clamp the jack strip against the stile strip because of the shape of each. This position of the fastener, as shown in FIG. 2, is designated the clamping position and is such as to hold the strip firmly against the supporting strip. Finally, the locking spacer 38 is clipped between the head of the screw and the butterfly.

To change the butterfly from a clamping position to a release position, the screw is rotated out of the tapped hole 23-. As the screw rotates, friction develops between the plastic bushing of the butterfly and the section 28. This friction is sufli'cient to turn or drive the butterfly in the same direction of the screw provided the butterfly is unrestrained. If the butterfly is held or otherwise restrained, such as by cold flow obstructions on the jack strip or object, the friction between the section 23 and the bushing will be exceeded which will bring the screw action of these members into operation. The screw action of these members causes the butterfly to translate along the screw or elevate with respect to the jack strip as the screw is rotated out of the tapped hole. The translation of the butterfly will continue with the rotation of the screw until the obstruction on the jack strip is cleared. Thereafter, friction will again cause the butterfly to rotate with the screw until the ridge 25 of the stile strip is engaged, the relief 36 permitting the butterfly to turn in the direction of screw rotation. This position of the butterfly is designated the release position of the fastener and is shown in FIG. 1.

In the release position and in the absence of the looking spacer38, it is possible to rotate the screw out of the tapped hole. As the screw is rotated, the holding action of the ridge causes the butterfly to translate along the screw. For continual rotation of the screw it will be seen that the butterfly will be elevated eventually above the ridge and thereafter the screw will be withdrawn from the tapped hole.

The locking spacer will prevent removal of the screw from the tappedhole 23 provided the width of the spacer is selected such that the butterfly cannot be elevated above the ridge 25. For a spacer of the width described, the butterfly will engage the spacer before reaching the top of the ridge. As a'result, the spacer will prevent upward movement of the butterfly while the ridge prevents rotational movement thereof. These restrictions on the butterfly will prevent the screw from being turned and thereby prevent the screw from being rotated out of the tapped hole.

To return the butterfly to a clamping position, the screw is advanced into the tapped hole. Upon rotation of the screw, the butterfly rotates therewith by friction until the unrounded corner thereof engages the ridge. Thereafter, continued rotation of the screw will cause a slip clutch actionbetween the bushing and the screw while the screw action of the section 28 and the bushing cause the butterfly to translate along the screw toward the jack strip. As previously explained, further rotation of the screw after the butterfly engages the jack strip causes the strip to be wedged against the stile strip.

Another embodiment of the fastener of the present invention is shown in FIGS. 3 and 4 wherein the elements identical to those disclosed in FIGS. 1 and 2 are designated with corresponding numbers.

The fastener 50 of FIG. 3 comprises a bolt or screw 26 and a clamp bar or butterfly 52 which includes a dowel or pin 54 coined or otherwise formed, or attached to the butterfly. The butterfly does not include a plastic bushing as in the first embodiment of the present invention. Instead a locking friction spacer 56, shown in FIG. 3A, is clipped on the screw between the head thereof and the butterfly, the spacer including a portion that encloses the dowel or pin 54.

The embodiment of FIG. 3 is assembled in the same manner as that of FIGS. 1 and 2, that is, the screw is threaded through the butterfly which is thereafter held in a clamping position while the screw is threaded into the tapped hole 23. The locking spacer is clipped about the bolt and pin after the former has been sufficiently threaded into the desired tapped hole.

To place the fastener of FIGS. 3 and 4 in a release position, it will be seen that when the screw is rotated out of the tapped hole the friction between the spacer and the screw will move the butterfly to the release position provided, of course, the butterfly is unrestrained. If the butterfly is restrained, as in the case of FIGS. 1 and 2, it will be elevated off of the jack strip until unrestrained and thereafter it will rotate by friction until it engages the ridge. The screw will slip in the spacer when the butterfly engages the ridge as in the case of the embodiment of FIGS. 1 and 2. The spacer width is selected to limit the translation of the butterfly to a distance less than that of the ridge, since as previously explained, the fastener will thereby be prevented from being withdrawn from the tapped hole.

It will be seen from FIGS. 1 and 3 that both embodiments of the fastener of the present invention in a quar-. ter of a turn automatically position the butterfly in a clamping position to clamp a jack strip against a supporting strip. No special tools are required to operate the fastener, and the fact that it may be hidden by connecting wires from an operator does not hinder the operation of the fastener.

The elevating or translating feature of the fastener insures positive-action upon operation thereof. Any obstruction to the butterfly caused by cold flow of the jack strip or overflush surfaces will be cleared when the fastener is operated, the butterfly thereafter rotating by friction to the release position.

The action of the locking spacer and the indexing ridge in preventing accidental removal is especially desirable in hidden or enclosed areas. The replacement of a fastener in such a location is time consuming as Well as being a possible safety hazard in connection with a PBX board. The fastener is readily removed from a stile strip by simply removing the locking spacer and rotating the screw until it is withdrawn from the tapped hole.

It is apparent that the above-illustrated embodiments are only representative of the principles of the present invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention.

What is claimed is:

1. A fastener for securing an object against a supporting strip having at least one tapped hole therein and an indexing ridge thereon, said fastener comprising a bolt having two threaded sections of different diameter and pitch, the larger diameter section being threaded into a clamping bar including a tapped bushing therein and having a dowel pin coined therein, means for driving said clamping bar through said dowel pin as rotation of the bolt occurs, said tapped bushing furnishing friction means thereby limiting in one direction the translation of the clamping bar along the larger diameter section for one direction of rotation of the bolt, the smaller diameter section being threaded into the tapped 'hole until said clamping bar is seated on said supporting strip and extended away from said indexing ridge, the bolt being rotated out of the tapped hole to place the clamping bar in line with said ridge and elevated above the supporting strip.

2. The fastener as defined in claim 1 wherein the clamping bar includes a relief at one corner thereof.

'3. In combination, a supporting strip and a fastener for securing an object against said supporting strip which includes at least one tapped hole therein and an indexing ridge thereon, said fastener comprising a two-ended bolt having a head at one of the ends and two threaded sections of different diameters and pitch at the other end, the larger diameter section being threaded into a clamping bar including a tapped bushing therein, said bushing forming a friction clutch with said larger diameter section, whereby rotation of the bolt in one direction drives the smaller diameter section into the tapped hole until said clamping bar is seated on said supporting strip and extended away from said indexing ridge and rotationv of the bolt in the other direction withdraws the smaller diameter section from said tapped hole and places the clamping bar in line with said ridge and elevated above said strip, and means for limiting the elevation of said clamping bar above the indexing ridge and rotation of the bolt in the direction of extraction, said limiting means further comprising a locking spacer clipped about the bolt between the head thereof and the clamping bar, said spacer having a width to limit the elevation of the clamping bar to a distance less than the height of the indexing ridge.

4. A fastener for securing an object against a supporting strip having at least one tapped hole therein, said fastener comprising a bolt having a head at one end, a smaller diameter threaded section at the other end, and a larger diameter threaded section with threads of greater pitch and in reverse direction to those in said smaller diameter section intermediate said head and said smaller diameter section, said smaller diameter section being threaded into said tapped hole in said supporting strip, said larger diameter section lacing threaded into a tapped bushing in a clamping bar, said clamping bar being connected to said bolt by a torque transmitting means and so shaped mat acting in concert with an indexing means said clamping bar Will be selectively positioned according to the direction of bolt rotation, and means for limiting the axial displacement of said clamping bar along said larger diameter threaded section toward said bolt head and rotation or said bolt in the direction of extraction, said limitir means comprising a spacer means disposed about the bolt between .the head thereof and said clamping bar and the indexing means comprising a ridge afiixed to the supporting strip whose height from the supporting strip is greater than the distance from the supporting strip to the surface of the clamping bar nearest the supporting strip When said clamping bar is abutting said spacer means.

5. A fastener comprising a bolt having a first threaded section of a first predetermined pitch and hand for insertion in a threaded hole, a clamping Ibar having a threaded aperture for receiving the belt, a ridge spaced from said bar for limiting rotation of the bar With the bolt, means mounted on the clamping bar for rotating said bar with said bolt into engagement With said ridge, a second threaded section formed on said bolt to engage the threaded aperture for translating said clamping bar along said bolt and said ridge, said second threaded section being of a hand opposite to the first threaded section and having a pitch greater than said predetermined pitch, and a spacer interposed between the 'bolt head and the clamping bar and having :a width suflicient to preclude translation of the bar past the ridge.

6. A fastener comprising a clamping bar having an aperture therein, a 'bolt extending through said aperture and having a first threaded section of a first hand, a ridge spaced from said clamping bar for engaging and limiting rotation of the clamping bar with the bolt, means mounted on said clamping bar for rotating said clamping bar with said bolt into engagement with said ridge, a second threaded section of opposite hand on said bolt engaging said rotating means for translating said clamping bar along said bolt toward the bolt head at a greater rate than the rate of extraction of the bolt, and spacing means positioned about the bolt between said clamping bar and the bolt head and having a Width sufficient to preclude translation of the clamping bar past said ridge.

7. A fastener comprising a bolt having a first threaded section of a first hand and a predetermined pitch for insertion in a threaded hole and a second threaded section of an opposite hand and a second predetermined pitch greater than the first, a clamping bar having an aperture for receiving the bolt, means carried by the clamping bar and engaging the second threaded section for rotating the clamping bar with the bolt during extraction of the first threaded section from the hole and for translating the clamping bar along the bolt upon limitation of the rotation of the clamping bar, means for limiting rotation of the clamping bar with the bolt, Whereafter the clamping bar translates along the bolt, and a removable spacer interposed between the clamping bar and the bolt head and having a width sufiicient to preclude translation of the clamping bar past the limiting means.

References Cited in the file of this patent UNITED STATES PATENTS 525,842 Edward Sept. 11, 1894 562,622 Kregel June 23, 1896 1,327,011 Arndt Jan. 6, 1920 1,826,817 Olley Oct. 13, 1931 2,010,525 McHugh Aug. 6, 1935 2,403,247 Sullivan July 2, 1946 2,445,396 Gursky July 20, 1948 2,485,280 Grace Oct. 18, 1949 2,896,295 Fischer July 28, 1959 

3. IN COMBINATION, A SUPPORTING STRIP AND A FASTENER FOR SECURING AN OBJECT AGAINST SAID SUPPORTING STRIP WHICH INCLUDES AT LEAST ONE TAPPED HOLE THEREIN AND AN INDEXING RIDGE THEREON, SAID FASTENER COMPRISING A TWO-ENDED BOLT HAVING A HEAD AT ONE OF THE ENDS AND TWO THREADED SECTIONS OF DIFFERENT DIAMETERS AND PITCH AT THE OTHER END, THE LARGER DIAMETER SECTION BEING THREADED INTO A CLAMPING BAR INCLUDING A TAPPED BUSHING THEREIN, SAID BUSHING FORMING A FRICTION CLUTCH WITH SAID LARGER DIAMETER SECTION, WHEREBY ROTATION OF THE BOLT IN ONE DIRECTION DRIVES THE SMALLER DIAMETER SECTION INTO THE TAPPED HOLE UNTIL SAID CLAMPING BAR IS SEATED ON SAID SUPPORTING STRIP AND EXTENDED AWAY FROM SAID INDEXING RIDGE AND ROTATION OF THE BOLT IN THE OTHER DIRECTION WITHDRAWS THE SMALLER DIAMETER SECTION FROM SAID TAPPED HOLE AND PLACES THE CLAMPING BAR IN LINE WITH SAID RIDGE AND ELEVATED ABOVE SAID STRIP, AND MEANS FOR LIMITING THE ELEVATION OF SAID CLAMPING BAR ABOVE THE INDEXING RIDGE AND ROTATION OF THE BOLT IN THE DIRECTION OF EXTRACTION, SAID LIMITING MEANS FURTHER COMPRISING A LOCKING SPACER CLIPPED ABOUT THE BOLT BETWEEN THE HEAD THEREOF AND THE CLAMPING BAR, SAID SPACER HAVING A WIDTH TO LIMIT THE ELEVATION OF THE CLAMPING BAR TO A DISTANCE LESS THAN THE HEIGHT OF THE INDEXING RIDGE. 